Effects of various cross-linked collagen scaffolds on wound healing in rats model by deep-learning CNN.

Scar tissue is connective tissue formed on the wound during the wound-healing process. The most significant distinction between scar tissue and normal tissue is the appearance of covalent cross-linking and the amount of collagen fibers in the tissue. This study investigates the efficacy of four types of collagen scaffolds in promoting wound healing and regeneration in a Sprague-Dawley murine model-the histomorphology analysis of collagen scaffolds and developing a deep learning model for accurate tissue classification. Four female rats (n = 24) groups received collagen scaffolds prepared through physical and chemical crosslinking. Wound healing progress was evaluated by monitoring granulation tissue formation, collagen matrix organization, and collagen fiber deposition, with histological scoring for quantification-the EDC and HA groups demonstrated enhanced tissue regeneration. The EDC and HA groups observed significant differences in wound regeneration outcomes. Deep-learning CNN models with data augmentation techniques were used for image analysis to enhance objectivity. The CNN architecture featured pre-trained VGG16 layers and global average pooling (GAP) layers. Feature visualization using Grad-CAM heatmaps provided insights into the neural network's focus on specific wound features. The model's AUC score of 0.982 attests to its precision. In summary, collagen scaffolds can promote wound healing in mice, and the deep learning image analysis method we proposed may be a new method for wound healing assessment.

The hemostatic effect and wound healing of novel collagen-containing polyester dressing.

Collagen plays an important role in hemostasis and tissue repair processes. Traditional passive wound dressings like gauze, bandage, and cotton wool could hardly fit the open wounds and exerted no active effect on wound healing. Even worse, they would adhere to the skin tissue, causing dehydration and second injury upon replacement. Polyester is commonly used in the medical field and is a safe and inexpensive polymer. Due to the hydrophobic surface, polyester does not adhere to tissue; however, polyester does not have the hemostatic properties. We designed a material composed of collagen and polyester, encapsulated hydrolyzed collagen in polyester particles, and made collagen-polyester non-woven fabric by melt blowing method, The collagen content was 1% and the collagen-polyester dressing exhibited a hydrophobic nature, preventing moisture from sticking to its surface. The purpose of this study was to compare the hemostatic effect of collagen-polyester nonwovens with conventional polyester pads, and to observe the adhesion of the pads to the wound. The wound healing and shrinkage rates of collagen-polyester dressings and conventional pads were compared in a rat wound healing test. The hemostatic test showed that the polyester pads containing 1% collagen significantly shortened the bleeding time compared with the traditional polyester pads, and retained the hydrophobicity and non-adhesion properties. The collagen-polyester dressing had better angiogenesis and granulation degree than the control group on the 14th day, and reduced the wound shrinkage rate. Collagen polyester dressings have excellent hemostasis, regeneration, shrinkage reduction and non-adhering for wounds. Overall, the novel collagen-containing polyester dressing is ideal choice for wound dressings.

A novel method for the detection of VEP signals from frontal region.

PURPOSE: This paper studies the feasibility of frontal positioning of electrode to detect electroencephalographic signals. METHODS: The experiments were conducted using a board with light-emitting diodes (LEDs) designed to stimulate SSVEP and FVEP. The flashing frequencies were conducted at 15, 23, and 31 Hz. We used the Quick Amp brain wave amplifier to collect brain wave signals at a sampling rate of 1 kHz using a frequency filter band of 10-100 Hz. RESULTS: We found that the energy power of VEP will gradually increase from Oz position to Fp2 position. We analyze the data, proving that the Fp2 position can also be used to collect VEP data. CONCLUSIONS: Traditional measurements at the Oz location are limited because of the interference from human hair, and an additional electrode is required to detect eye movement and filter this electro-oculogram signal. Our proposed method can effectively acquire critical visually evoked potential and electro-oculogram signals without the electrode at the Oz location, which require extensive preparation of removing hair strands. We also reduced the number of electrodes used in receiving electroencephalographic signals. The frontal electrode positioning could be a remarkable breakthrough to design brain computer interface.

Syntheses of (+)-complanadine A and lycodine derivatives by regioselective [2 + 2 + 2] cycloadditions.

The dimeric alkaloid complanadine A has shown promise in regenerative science, promoting neuronal growth by inducing the secretion of growth factors from glial cells. Through the use of tandem, cobalt-mediated [2 + 2 + 2] cycloaddition reactions, two synthetic routes have been developed with different sequences for the formation of the unsymmetric bipyridyl core. The regioselective formation of each of the pyridines was achieved based on the inherent selectivity of the molecules or by reversing the regioselectivity through the addition of Lewis bases. This strategy has been successfully employed to provide laboratory access to complanadine A as well as structurally related compounds possessing the lycodine core.

5-Oxo-ETE receptor antagonists.

5-Oxo-ETE is the most powerful eosinophil chemoattractant among lipid mediators. Eosinophil infiltration into the lungs of asthmatics may be responsible for the late phase of inflammatory asthma. We have designed and synthesized a 5-oxo-ETE receptor antagonist, the purpose of which is to prevent eosinophil migration to the lung during an asthma attack and thereby reduce asthma symptoms.

Synthesis of (+)-complanadine A, an inducer of neurotrophic factor excretion.

A total synthesis of the Lycopodium alkaloid (+)-complanadine A is described. Complanadine A has been shown to induce the secretion of neurotrophic factors from 1321N1 cells, promoting the differentiation of PC-12 cells. The use of a simplifying metal mediated [2+2+2] + [2+2+2] sequence using a silyl-substituted diyne and 2 equiv of the corresponding alkyne-nitrile has provided rapid access to the natural product.

A new approach to the synthesis of polyunsaturated deuterated isoprostanes: total synthesis of d4-5-epi-8,12-iso-iPF3alpha-VI and d4-8,12-iso-iPF3alpha-VI.

The total and stereospecific synthesis of d(4)-5-epi-8,12-iso-iPF(3alpha)-VI 55 and d(4)-8,12-iso-iPF(3alpha)-VI 64, EPA-derived all-syn-isoprostanes (iPs), has been accomplished. Because of issues related to volatility and yield with some of the primary deuterated synthons an improved synthesis is presented. These two deuterated analogs were used to discover and quantify the presence of the corresponding endogenous isoprostanes in human urine. These assays may serve as a valuable index of oxidative stress in population with omega-3 fatty acid enriched diets containing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and may also be useful as an index of the severity of inflammatory diseases such as atherosclerosis and Alzheimer's disease.

Novel eicosapentaenoic acid-derived F3-isoprostanes as biomarkers of lipid peroxidation.

Isoprostanes (iPs) are prostaglandin (PG) isomers generated by free radical-catalyzed peroxidation of polyunsaturated fatty acids (PUFAs). Urinary F(2)-iPs, PGF(2alpha) isomers derived from arachidonic acid (AA) are used as indices of lipid peroxidation in vivo. We now report the characterization of two major F(3)-iPs, 5-epi-8,12-iso-iPF(3alpha)-VI and 8,12-iso-iPF(3alpha)-VI, derived from the omega-3 fatty acid, eicosapentaenoic acid (EPA). Although the potential therapeutic benefits of EPA receive much attention, a shift toward a diet rich in omega-3 PUFAs may also predispose to enhanced lipid peroxidation. Urinary 5-epi-8,12-iso-iPF(3alpha)-VI and 8,12-iso-iPF(3alpha)-VI are highly correlated and unaltered by cyclooxygenase inhibition in humans. Fish oil dose-dependently elevates urinary F(3)-iPs in mice and a shift in dietary omega-3/omega-6 PUFAs is reflected by an increasing slope [m] of the line relating urinary 8, 12-iso-iPF(3alpha)-VI and 8,12-iso-iPF(2alpha)-VI. Administration of bacterial lipopolysaccharide evokes a reversible increase in both urinary 8,12-iso-iPF(3alpha)-VI and 8,12-iso-iPF(2alpha)-VI in humans on an ad lib diet. However, while excretion of the iPs is highly correlated (R(2) median = 0.8), [m] varies by an order of magnitude, reflecting marked inter-individual variability in the relative peroxidation of omega-3 versus omega-6 substrates. Clustered analysis of F(2)- and F(3)-iPs refines assessment of the oxidant stress response to an inflammatory stimulus in vivo by integrating variability in dietary intake of omega-3/omega-6 PUFAs.

Eicosapentaenoic-acid-derived isoprostanes: synthesis and discovery of two major isoprostanes.

The stereospecific synthesis of two all-syn-EPA-derived isoprostanes (iPs), 5-epi-8,12-iso-iPF(3alpha)-VI 17 and 8,12-iso-iPF(3alpha)-VI 18, has been accomplished. These two synthetic probes have been used to discover and identify their presence in human urine. The eventual quantitative measurement of these two iPs may be a valuable index of oxidative stress in people with eicosapentaenoic acid- (EPA) and docosahexaenoic acid- (DHA) enriched phospholipids.

Neurofurans, novel indices of oxidant stress derived from docosahexaenoic acid.

Isoeicosanoids are free radical-catalyzed isomers of the enzymatic products of arachidonic acid. They are formed in situ in cell membranes, are cleaved, circulate, and are excreted in urine. Isomers of prostaglandin F(2alpha), the F(2)-isoprostanes, have emerged as sensitive indices of lipid peroxidation in vivo. Analogous compounds formed from docosahexaenoic acid (DHA) are termed neuroprostanes and are more abundant than isoprostanes (iPs) in brain. Isofurans are another class of isoeicosanoids characterized by a substituted tetrahydrofuran ring. They are preferentially formed, relative to iPs, under conditions of elevated oxygen tension. Here, we report the discovery of neurofurans (nFs), the analogous family of compounds formed from DHA. Formation of nFs is characterized by mass spectrometry and confirmed by oxidation of DHA in vitro and following CCl(4) administration in liver in vivo. It is demonstrated that the levels of nFs are elevated in the brain cortex of a mouse model of Alzheimer disease and are depressed in mouse brain cortex by deletion of p47(phox), an essential component of the phagocyte NADPH oxidase. Measurement of the nFs may ultimately prove useful in diagnosis, timing, and selection of dose in the treatment and chemoprevention of neurodegenerative disease.

Reductive Deprotection of Silyl Groups with Wilkinson's Catalyst/Catechol Borane.

Traditionally silyl groups are deprotected with acids and fluorides. These methods are, however, less discriminating when multi-silyl groups are present in the same molecule resulting in lower yields of desired products. The manipulation of these functions during the total synthesis of natural products, e.g. prostaglandins and isoprostanes, requires the selective protection and deprotection of these groups.We are reporting here on a mild, selective and efficient method for the reductive deprotection of silyl groups using Wilkinson's catalyst/catechol borane or catechol borane alone.

Total synthesis of 8,12-iso-iPF3alpha-VI, an EPA-derived isoprostane: stereoselective introduction of the fifth asymmetric center.

[reaction: see text] A new and stereoselective approach for the synthesis of all-syn isoprostanes is reported. This method, which is based on acid-catalyzed Diels-Alder reaction, allows the introduction of the side chain with a predetermined stereochemistry of the hydroxy group. The first total synthesis of an eicosapentaenoic acid (EPA)-derived iP, 8,12-iso-iPF3alpha-VI 10, was performed using this approach.